The invention relates to a method for monitoring the condition of a vehicle driver, in which a vehicle's position in a lane is detected and monitored, a direction of travel is determined, the actual position in the lane is compared with the direction of travel which is determined, and the driver is assisted in maintaining the position in the lane.
A method of this type is disclosed in EP 0 640 903 A1.
More and more tasks are being taken away from the driver by auxiliary means such as distance-control systems, cruise-control arrangements and lane assistants. These systems are used with the aim of making road traffic safer. In particular, accidents caused by drivers not paying attention should be avoided. However, a large number of such systems may be subject to misuse. Since systems of this type do not ensure complete safety, care should be taken that the driver continues to assume responsibility for driving the vehicle in spite of these systems assisting him.
EP 0 640 903 A1 discloses a system for assisting a driver in which a video camera or the like is arranged on a vehicle. This video camera is used to identify the lane or carriageway markings on the road. An associated signal processor estimates the lateral position of the vehicle in relation to the carriageway markings. An electric motor which is connected to the steering system is used to introduce torque into the vehicle steering arrangement which either assists the steering torque produced by the driver or counteracts it. The signal processor is formed such that it assists the driver in maintaining the vehicle's position in the lane. As a result, a channel-like carriageway in which the vehicle has to be kept is simulated. In this case, the driver can disengage driver assistance by the vehicle by introducing a sufficiently large steering torque. In particular, provision is made, when the vehicle approaches a carriageway marking, for a warning signal to be emitted as a sign that the vehicle is not moving in a calculated direction of travel. This should startle the driver so that he returns to the correct position on the carriageway.
The object of the present invention is to provide a method which can be used to identify when a driver is no longer actively steering the vehicle.